Cylinder grinding tool



Oct. 12, 1943. F. s. WACKER 2,331,523

' CYLINDER GRINDING TOOL Filed'Nov. 24, 1941 3 Sheets-Sheet l v i 41INVENTOR.

Oct. 12, 1943. F. a. WACKER 2,331,523

CYLINDER GRINDING TOOL Filed Nov. 24, 1941 3 Sheets-Sheet 2 1N VENTOR,

F. s. wAcKER CYLINDER GRINDING TOOL Filed Nov. 24, 1941 3 Sheets-Sheet 3Patented Oct. 12, 1943 CYLINDER GRINDING TOOL Frederick G. Wacker, LakeForest, Ill., assignor to Automotive Maintenance Machinery 00., North.Chicago, 111., a corporation of Illinois Application November 24,194.1,Serizil No. 420,224

21 Claims.

My invention relates to cylinder grinding tools and it has to do with atool of a character particularly well suited for use in the factoryproduction field.

One of the objectsof my invention is to provide an improved tool of theforegoing character which is compact and durable, which may bemanufactured cheaply, and which is adapted for greater accuracy andeficiency in the grinding of cylinders. 7

Another object is to provide a tool of'the foregoing character having animproved drive.

- A further object is to provide improved means for positivelydetermining the extent of grinding, which means cooperates withadjustable tool expanding mechanism to grind aparticular cylinder to apredetermined-extent and to insure the grinding of successivecylindersto the samepredetermined size. I I

An additional'object is to provide a tool of the foregoing characterwherein the grinding operation may be carried on under variablepressures, to accommodate the grinding of materials of varying hardnesswith a minimum of wear and deterioration of the grinding members, aswell as to accommodate varying conditions. in the grinding of the samematerial, all to-the end that the grinding operation may be carried outmore quickly, accurately andeificiently.

Another object is to provide a cylinder grinding tool having its partsconstructed and arranged for precision grinding operation. v

Still another object is to provide-a cylinder grinding tool havingadjusting mechanism so constructed and arranged that it is independentof the tool driving mechanism whereby the tool adjustment is notaffected by disalignmentbe tween the tool and its driving means, theadjusting mechanism is free of joints which tend to wear andcausemisadjustment of parts of the adjusting mechanism, and is notaffected by wear and looseness of parts of the driving mechanism. Afurther object is to provide a cylinder grind.- ing tool adapted for thegrinding of cylinders of varying lengths, which tool, however, is soconstructed and arranged as to substantially reduce the height of thetool and its driving means.

Another object is to provide a cylinder grinding tool adapted forthegrinding of a wide range of cylinder diameters. An additional objectis to provide a cylinder grinding tool having a rigid body with-axiallyspaced end plates supporting radially expansible abrasive carriers, thetool being driven through a universal joint connecting a driving spindlewith the lower or bottom end plate of thetool body.

A further object is to provide improved spring type retracting meansopposing radial expansion of the stone carriers. v

- Other objects and advantages will become apparent as this descriptionprogresses and by reference to the drawings, wherein- Figure 1 is avertical sectionalview, partially in elevation, showing one form of toolembodying my invention, which view. is taken substantially onlinel--| ofFig. 3;

Fig. 2 is a fragmental ,elevational view of the pressure indicatingmeans shown'in Fig.1; Fig. 3 is asection taken substantiallyon line 3-3of Fig. 1; r Fig. 4 is a section taken substantially, on line 44 of Fig.1; Fig. '5 is a partial bottom-plan view of the structure shown, in Fig.1; Fig. fi-isa fragmental sectional'view ofan abrasive c arrier having agrinding stone unit mounted therein, and illustrating an improved formof interlock between the abrasive "carrier and the stone unit; and v--Fig. 7 is a view similar to Fig. 4 illustrating an improved form ofspring support for the stone icarriers. I r i The tool shown in thedrawinga while being especially adapted for so-called production use,may also beused in the service vfield or in any other field .where itmay have utility. In production use of a tool of this type, itis usuallydriven by amachine (not shown) having a driving spindle. Referringparticularly to the tool shown in Figs. 1 to 5, inclusive, the machinespindle is provided with ahead 20 which is drive-connected to one end ofa tool spindleil by a universal drive connection 22. (Fig. 1). The otherend of the tool spindle II is connected to the tool bodynvhich will nowbe described.

Thetool body, which is of the so-called rigid frame type, includesaxially spaced apart top and bottom plates 23 and 24 which are rigidlyjoined together by circumferentially spaced posts, 25. The posts 25,preferably, have theirends riveted in the bottom plate 24 and; their.upper ends threaded and passing through openings'in the top plate 23 toreceive nuts 26 which, when tightened, provide a rigid cage-likeiramestruc ture with passageways between the posts 25jfoi the mountingof abrasive carriers.

- The bottom plate. 24 is o iless diameter than the top plate 23 for apurpose which will be de scribed later, and the facing surfaces of theend plates are provided with radially directed grooves 21 and 23,respectively, for receiving and adjustably supporting abrasive carriers29. All of the abrasive carriers are of like construction and only onewill be described in detail.

The abrasive carriers are sometimes referred to as stone carriers andeach includes a flat, rectangularly shaped body portion 33 having endtongue-like portions 34 which are snugly and slidably received in theend plate grooves 21 and 28 for radial expanding movement of the stonecarrier. The outer edge portion of the carrier is provided with athickened head portion which is slotted to provide a longitudinallyextending channel 32 in which is received a. grinding stone unit 33.This latter unit includes a channel. member 34 in which is secured agrinding stone 35, the stone unit being securely locked in the carrierchannel 32 by a longitudinally extending block 36 engaging one side ofthe stone unit channel member 34 and secured to the stone carrier byscrews 31. In order that the stone unit may be trictiona'lly clamped inplace by the block 36, such unit is just slightly wider" than thecarrier channel 32 so that the desired g pping action will beaccomplished when the block 38 is tightened in place by the screws 3T.The grinding stone 35 is, preferably, adhesively secured to itssupporting channel 34, and the block 36 is solely relied upon to holdthe stone unit 33 in place. However, if desired, the channel member maybe additionally and positively secured to the stone carrier" in themanner illustrated in Fig. 6. More particularly, the channel member 34of the stone unit 33' is provided, at each side, with struck-outportionsrrolled outwardly to provide bead-like elements 34". The stoneunit 33 is clamped in place by a block 36 which forms one side of thestone unit receiving channel or the stone carrier 29. The block 36" andthe other side of the carrier channel are provided with notches 29 inwhich the bead-like elements 34" are received.

Although my invention W is adapted for the grinding of dififerent typesof cylinder bores, the tool shown in Fig. 1 is adapted particularly forthe grinding of so-called blind bores, or bores with a. closed bottomwherein the tool cannot be reciprocated through and partially beyond thebottom of the bore. In that case itis desired that the grinding actionbe carried onto the full depth of the stroke oflthe tool and, toaccomplish that, the outer edge of the stone carrier is pro vided with alower over-hang portion 38 which extends downwardly over the outerperipheral surface of thereduced-diameter bottom' plate 24. When openbores are to be ground and this over hang is not desired, the carriermay be formed as shown in Fig. 6 and the bottom plate 24' maybe the samediameter as the top plate. Again referring to Fig. l, the carriers 29are retained against outward displacement from the grooves 21 and 20' bya pair of' garter springs 39 and 40 located at'the opposite ends of thecarriers. The upper garter spring 39 is seated in a complementallyshaped slot in each of the upper carrier tongues 31-, while the lowerspring 40 is carried'by an annularly disposed group of spool-likemembers-41 having stems 42 fixedly mounted in" the over-hanging portions38 of the carriers. i I

The stone carriers 29 are radially supported by a centrally disposedcone-type expander unit 43 which is shiftable axially to expand thecarriers 29' radially outward. This cone unit comprises a tubularstem-like portion 44 slidably mounted in and passing through an opening45 in the top plate 23. The stem 44 extends through the central portionof the body to near the lower end thereof and it is provided, within thebody, with a pair of axially spaced integral cones 46 and 41. Thesecones are received in complementally shaped slots 48 formed in the inneredges of the carriers 29 whereby, when the cone unit 43 is shiftedupwardly, the carriers 29 are expanded radially outward, being held infirm engagement with the cones by the garter springs 39 and 40 and, whenit is shifted in the opposite direction, the carriers are contractedthrough the action of the garter springs 39 and 40. The springs 39 and48 are comparatively weak, exerting only sufi'icient pressure to holdthe carriers 29 firmly seated against the cones 46 and 41 and tocontract the'carriers when the cone unit is moved in tool-contractingdirection.

The cone unit 43 is further supported for axial movement by a centraltubular member 49 disposed within and throughout the length of the coneunit tube 44 and projects therebeneath for rigid connection with thebody bottom plate 24. More particularly, the lower end of the tubularmember 49 is provided with an offset, increaseddiameter portion 49 whichextends through an opening in the bottom plate 24, the lower portion ofsuch extending part being outwardly flanged at 50 and received in arecess 5| in thebottom plate. The flange'50 is secured to the bottomplate 24 by an annular series of stud-and-bolt devices 52 (Fig. 5). Inthis manner the tubular member 49 is rigidly fixed to the body and itserves as a slide support for the cone unit 43, the lower cone 4! ofsuch unit being cut back and complementally shaped to accommodatethelower offset portion 49 of the member 45. i

The tool is driven from -the bottom plate 24 through the spindle 2! andthe tubular member 49. To this end, the lower end of the tubular member49 is provided with diametrically opposed slots 53 in which is receivedthe pin 54 carried by a ball end 55 on the lower end of the spindle 2|and formin part of a universal joint. The upper surface of the ball end55 is seated against a two-part circular ring 56 having a shoulder 56engaging a shoulder on the tubular member 49 provided by the offsettingof the portion 49"- thereof. The ring 56 is provided with a lower curvedbearing surface 55 against which the ball 55 seats. The ball end 55 isretained in driving relation by a nut 51 mounted in the lower threadedend of the tubular member 49, which nut is provided with a curvedbearing surface 5'! against which the lower part of the ball 55 seats.The nut 51 is split as at 51' and is provided with a threaded openingthrough the split portion for reception of a threaded lock stud 58which, when tightened, securely locks the nut in place. The ring 55 andthe nut 5'! Serve as confining thrust bearings for the ball end 55 ofthe spindle 2|. Also, the slots 53 in which the universal pin 54 isreceived are elongated sufficiently; to permit the pin and, in turn, thespindle to rock in a direction at right angles to the rotary movementpermitted by such pin, thereby providing a joint affording universalaction of the spindle 2 I.

In the use of a tool of the foregoing character, it is highly desirablethat the pressure With which the grinding stones 35 are engaged with thecylinder wall, as well as the extent of the grind lng operation, becontrolled. For most efficient employed.

operation, a different grinding pressure is desirable for grindingmaterials of different hardness. Also, a different or initial and lesserpressure is desirable for initially grinding a newly turned or formedcylinder for preliminarily removing tool marks and high points. It hasbeen found that if the full grinding pressure is initially employedbefore the tool mark and high points are removed, there is a tendency torapidly break down or tear apart the grinding stones, materiallyreducing the life thereof. My invention takes care of the foregoingcondition in a new and novel manner in which difierent unit stonepressures are effectively employed for grinding different materials orhandling different conditions of the same material.

Specifically, during the grinding operation, the stone carriers 29 arautomatically expanded under the control of a spring 59 which may beadjusted or loaded to obtain different unit stone pressures as well asto effect a desired range of carrier expansion. To the foregoing end,the spring 59 surrounds the upper tubular portion '54 of the cone unit43 with its lower end seated against the top end plate 23. The upper endof the. tubular portion 44 of the cone unit 43 is externally threaded toreceive an adjusting nut ,60 having a reduced-diameter skirt portion 6!which extends down over and houses the upper end of the spring 59 whichis confined between the'top end plate 23 and the adjusting nut 60.

It will be seen by reference toFig. 1 that when .the nut 60 is screweddownwardly the spring 59is compressed so as to yieldingly urge the, coneunit 43 and the nut 69 upwardly and, in turn, expand the carriers 29against the slight pressure exerted by the garter springs '35; and 473.Therefore, with the carriers retracted, the tool may be inserted in acylinder and the nut 50 screwed downwardly, expanding the carriers untilthe grinding stones 35 seat against the cylinder wall. No furtherexpansion of the stone carriers Will take place until the grindingoperation occurs. However, to insure the grinding operation underpressure, after the stones have been set against the cylinder wall, theadjusting nut is screwed downwardly to an additional and predeterminedextent, thereby placing the spring 59 under additional compression forexerting a I selected grinding pressure. In that I way the spring 59 iscaused to urge the grinding stones against the cylinder wall under anyaccurately determined unit stone pressure. There is a definiterelationship between the threads of the ad- ,justingnut 69 and thethreads on the tubular part 44 of the cone unit 43, and between thecones 45 and 41 and the carrier surface engaged thereby, whereby acertain compression of the spring 59 by turning down the nut 550 to apredetermined extent produces acertain spring load exerting apredetermined unit, stone pressure. By unit stone pressure I mean thepressure applied over each square inch of stone area in engagement withthe cylinder wall.

In order that the operator may accurately j determine the unit stonepressure employed, I

provide a scale 52 carried by and extending upwardly from the top endplate 23 in alignment with the lower edge of the nut skirt 6!. The nutskirt BI is provided at its bottom with a V-shaped flange 63 providing arather sharp peripheral edge 6? coinciding with the scale 62. The scale62 is, preferab1y,f calibrated to indicate in terms of pressure the unitstone pressure In other words, as the nut Bil is screwed upwardlyor'downwardly along the scale 62 at any predetermined position alongthe'sca-le, the tool is set for a certain unit stone pressure.

When the tool is in a cylinder and adjusted for v throughout the rangeof grinding operation the spring 59 exerts a substantially constant oruniform unit stone pressure against the cylinder wall. In the honing ofcylinders formed of cast iron or-mild steel '2. maximum unit stone pres'sure ranging fromtwenty to thirty pounds may be employed in finallygrinding the cylinder. If it is a newly formed cylinder, the adjustingnut may be initially setfor a unit pressure of ap-' proximately fivepounds and the tool bperated' to grind "down the tool marksand highp'oints. After this has been done the tool may then be stopped and thenut 60 adjusted to the maximum working pressure, after whichthe grindingoper-- ationis continued. In boring cylinders formed of harder material,greater pressures maybe employed, the particular a pressure dependingupon the hardness of the material. I

It'is desirable for accuracy in the grinding of a single cylinder asWell as successive cylinders and for facilitating the work of theoperator so "her 49 is ext'eriorly threadedgand an adjustable stop nut64 'is mounted thereupon; This stop nut is provided with an upperexteriorlyeknurled portion 64 that may be grasped for ready ad-'justment of thesame, and a lower reduced portion av a scale" 65 thereoncalibrated to indica'te expansion of the stone carriers 29 inthousandths of an inch." In other Words, the threads of the nut 64 areso related to the threads of the tubular member 49 that the extent ofscrewing the nut 6411p or down on the member 49 is represented in termsof thcusandths of an inch onthe scale 65. As hereinabove explained;

the cone unit 43 is moved upwardly in expanding thestone carriers29--hence, by disposing the stop nut 64 axially in the path of upwardmovement of the'upper end of the tubular portion 44 of the cone unit43,.the'extent-to which the stone carriers may expand' may be definitelydeter mined. To this end, the lowerpart of the nut 64be'neath thescalel65 is provided with a reduced circumferential rim or bead-likeportion 66 whichis disposed in. vertical alignment with the upper end ofthe cone unit tube 44. In use, ypreferably after the pressure. adjustingnut has been set up to just engage the grinding stones 35 with thecylinder-wall, the nut 64' is screwed downwardly into engagement withthe upper end of the cone tube 44. The operator then notes the positionof the scale 65 with respect to the indicating elementfi'l carried bythe nut 68 and,

if it is desired to remove, for example, .0101,

material from the cylinder wall, the nut. 64 is.

'backed away from the upper end of the tube-44 .010", as indicated onthe scale 65. It will be appreciated that in removing .010" materialfrom the wall of a cylinder, the grinding stones will wear away to acertain extent, for example, .005 in the grinding of a. cast ironcylinder. Therefore,.in order to more accurately remove .010" materialfrom the cylinder wall, the operator will back the nut 64 away from theend of the cone tube 44 an additional .005", or a total of .015". Thisnut 64 is then looked in that set condition by the lock stud 68 passingthrough a slitted portion of the nut, as best shown in Fig. 1. When thegrinding operation is carried on, thestone carriers will gradually beexpanded as material is removed from the cylinder wall, the cone unitgradually moving upwardly until its upper end finally strikes the bead66 on the stop nut 64, when the tool can no longer expand and no furthermaterial will be removed from the cylinder wall. The tool may then beremoved from the cylinder by adjusting the nut 68 upwardly to unload thespring. If another cylinder is to be similarly ground, the pressure nut60 is adjusted upwardly to contract the stone carriers to per mit thesame to be inserted in the new cylinder. When that is done and the toolis inserted in the next cylinder, if the same amount of material is tobe removed, the stop nut 64 need be further adjusted to merelycompensate for stone wear and thenut 60 is adjusted to load the spring59 for the proper unit stone pressure.

The cones 46 and 41 are additionally supported andguided by an annularrow of posts 69 carried by theend plates 23 and 24 and disposed inwardlyof the posts 25. The posts are located at such a point that they arereceived in radial slots II formed in the cones 46 and 41. With thisarrangement, the expander cones are not only additionally supported foraxial slide movement, but added rigidity is provided in the tool as awhole.

I! desired, the stone carriers may be yieldably held in engagement withthe expander cones and may be radially retracted by the springarrangement shown in Fig. 7. The tool shown in Fig. 7 is similar to thatpreviously described except that the garter springs 39 and 40 have beenomitted and individual leaf springs 80 substituted therefor. More.particularly, the frame end plates 8| (only one shown in Fig. 7) aresupported in spaced relation by an annular series of posts 82formingradial passageways in which are located stone carriers 83. Thesestone carriers are supported for radial slide movement by the end platesas described in connection with the form of Figs. 1 to 5. Each of theposts 82 supports, near its center, a spring 88 which comprises aplurality of spring leaves different lengths arranged in overlappingrelation. The posts 82 are disposed, preferably,

midway between the carriers 83, and the longer and innermost one of eachof the spring leaves extends into engagement with the two adjacentcarriers. Each of the springs 80 is secured to the posts 82 by a screw84 and washer 85. Each carrier 83 is provided with side lugs 88, 86.

against the outer faces of which the ends of the springs 80 seat andurge the carriers inwardly against the expander cones 81 (only one shownin Fig. 7). The springs 80 are so constructed and the parts are solocated relatively that, when the tool is fully contracted, the oppositeends of the springs 88 engage the lugs 86 and 86 of adjacent carriersunder a slight tension, holding the carriers yieldably engaged with thecones 81. Obviously, expansion of the carriers is yieldably opposed bythe springs which insure inward movement of the carriers when the toolis contracted.

It is believed that the operation and advantages of my invention will bereadily understood from the foregoing description. A tool embodying myinvention is of rugged construction, is compact and is well suited forproduction work. It is a precision tool capable of fine adjustment foraccurate cylinder grinding work. It insures the proper unit pressure forthe work to be done, thereby greatly increasing the efficiency of toolsof this kind. It insures the proper pressure for materials of varyinghardness as well as the proper pressure at different stages of grindinga particular material. This not only provides for a more efi'icient useof the grinding stones but a properly honed cylinder results in lesstime. The desired unit pressure is maintained substantially constantthroughout a wide range of expansion movement of the stone carriers,thereby efficiently accommodating the tool to a wide range of cylinderbores while insuring proper grinding pressure. The adjustment mechanismis so arranged that it is unailected, from the standpoint of accuracy,by the dust, grit, etc., resulting from the grinding operation.Looseness of parts and strains and stresses necessarily imposed on thedriving mechanism does not in any way affect the tool adjustment.Disalignment of the drive and the tool, which is compensated for by theuniversal drive connections, in no way affects the adjustment of thetool. In addition, the tool structure is quite simple and is quiteinexpensive to manufacture, all this being attained with a toolaffording greatly increased efficiency in the grinding of cylinders,whether they be newly formed or used and worn.

I claim:

1. A cylindergrinding tool comprising a body, grinding devices carriedby said body for movement toward and from a cylinder wall to be ground,a member movable relative to said devices to move said devices towardand from the cylinder wall, means for moving said member including anelement adjustably mounted directly upon and movable along said memberand .a compressible spring disposed between said element and said body,said spring being compressible to predetermined and variable extents byadjustment of said element along said member when said grinding devicesare engaged with the cylinder wall for automatically expanding saidgrinding devices as the grinding operation takes place and fordetermining the unit pressure employed during the grinding operation,and adjustable means adapted to be engaged by said member for limitingthe extent of movement of said grinding devices toward the cylinder wallduring the grinding operation.

2. A cylinder grinding tool comprising a body, grinding devices carriedby said body for movement toward and from a cylinder wall to be ground,a member movable relative to said devices to move said devices towardand from the cylinder wall, means for moving said member including anelement adjustably mounted upon and movable along said member and acompressible spring disposed between said element and said body, saidspring being compressible to predetermined and variable extents byadjustment of said element along said member when said grinding devicesare engaged with the cylinder iwallfor automatically expanding saidgrinding devices as the grinding operation takes place .and fordetermining the unit pressure employed during the grinding operation,and adjustable means for variably determining the extent of adjustmentof said grinding devices toward the cylinder wall by said spring. a a a3. A cylinder grinding tool comprising a body,

grinding devices carried by said body for movement toward and from acylinder wall to be- -ground, a member movable relative to saiddevicesto move said devices toward and from the cylinder wall, means formoving said member including an element adjustably mounted upon andmovable along said member and a compressible spring disposed betweensaid element and said body, said spring being compressible topredeterminedand variable extents by adjustment of said element axiallyalong said member,

means forindicating the extent of adjustment of said element in terms ofunit pressure applied to. said grinding devices, and adjustable meansment toward and from a cylinder wall to be ground, a member movablerelative to said -de vices to move said devices toward and from thecylinder wall, means for moving said member including an elementadjustably mounted upon and movable along said member and a compressiblespring disposed between said element and said body, said spring beingcompressible to predetermined and variable extents by adjustment of saidelement along said member, and an adjusting device carried by said bodyand adjustable to variable extents toward and from said member andadapted to be engaged by said member to. stop movement of said grindingdevices toward the cylinder wall when the cylinder has been ground to apredetermined extent.

A cylinder grinding tool comprising a body, abrasive members mounted insaid body for expansion and contraction movements toward and from acylinder wall to be ground, an expanding device supported in said bodyfor axial movement and having elements engaging said members for,expanding the latter, means for shifting said expanding device includinga member carried solely by said expanding device and adjustable axiallytherealong and a compression spring disposed between said member andsaid body and compressible to variable extentsv to move said expandingdevice and abrasive members to variable extents and to cause saidabrasive members to engage the cylinder wall under a predeterminedselected pressure, and adjustable means adapted to be engaged by saidexpanding device for limiting the extent of movement of said abrasivemembers relative to the cylinder wall after they have been initiallyengaged therewith.

6. A cylinder grinding tool comprising a body, grinding members mountedin said body for expansion andcontraction movements toward and from acylinder wall to be ground, an expanding device supported in said bodyfor axial movement and having elements engaging said members forexpanding the latter, means forpshifting said expanding device includinga member carried solely by said expanding device and adjustable axially.therealong and a compression spring disposed between said, member andsaid body and compressible to 'jv'ari'able extents to move saidexpanding device and grinding members to variable extentsandtocausefsaid grind- .ing members to engage the cylinder wall under apredetermined selected'pr'es's'ure, means for indicating the pressureunder wliich said grinding members are engaged "with thje'cylinder wall,and means carried by said body andfadapted to be adjustably disposed, inthe axial pathgof said expanding device for limiting'fthe extent ofexpansion of said'grinding members.

v7. A. cylinder grinding tool comprising a body, grinding devicesmountedinsaid body and movable toward and from a cylinder wall to beground, a member rigidlylsupported on the axis of said body, a secondmember supported by said first member for axial movement and havingelements thereon adaptedito engage and move said grinding devices towardthe. cylinder wall as said second memberismovedin onedirection, meansfor moving said'second member axially including an element carried bysaid second member and adjustable therealongla compression springconfine'dj'rbetween .said "element and said body andcompressiblejwhensaid grinding devices are engaged with the cylinderwall to automatically movesaidgrinding devices toward the cylinder walland tocause said grinding'de vices to engagetliecylin'der"wall under apredetermined pressure,and'means'carriedby and adjustable along saidfirst member. for engaging said second member. mama the'extent to whichthe cylinder wall may be ground. 5

8. Acylinder grinding tool'comprising a body, grinding memberssupportedflbyj said body for expansion and contraction movements, amember rigidly secured to and extending through the central portion ofsaid body, an expanding mem-' ber supported by said rigidly securedmember and movable axially to expand and contractsaid grinding members,means for moving said expanding member axially, and means carried bysaid rigidly securedlmember for lir'nitingthe extent of movement of;said'expanding member in one direction.

9. A cylinder grinding tool comprising a body, grinding memberssupported by said body for expansion and contractionmovementaa memberrigidly secured to and extending through the central portion of saidbody, an expanding member supported by said rigidly se'cured member' andmovable axially to expand and contract said grinding members,meansjinclu'ding an axially adjustable element on saidi expandingelement and a spring between said element and said body for moving saidexpanding member axially, and means carried by said rigidlysecuredmember for limiting the extent of, movement of; said expanding memberinone direction.

10. A cylinder grinding tool comprising a body, grinding memberssupported by said body for expansion and contraction movements, a memberrigidly secured to and extending; through the central portion of saidbody, an expanding member supported by said rigidly securedmemberandmovable axially to expand andvcontract said grinding members, ;means,including an axially adjustable element on said e xpanding element andaspring between said element and said body for moving said expandingmember axially; said spring being I compressible by said element toautomatically expand said expanding elementas the cylinder is beingground and toexert and maintain a substantially constantgrindingpresbodyifor expansion and contraction movements,

a tubular expansion member carried by said tubular part Iorfa'xialmovement and having elements engaging said grinding members to expandand contract the latter as said expansion member is moved axially, meansfor moving said expansion member axially including an adjustable elementon said expansion member and a spring urging said adjustable elementin'one direction,

means for variably limiting the extent of expansion of said grindingmembers by said expansion member, and drive means extending through saidtubular part and having a universal connection therewith,

12. A cylinder grinding tool comprising a body, grinding members mountedin said body for expansion and contraction movements, anexpanding'member carried by said body and movable axially thereof forexpanding and permitting contraction'of said grinding members, means formoving said expanding member including an axially adjustable element onsaid expanding memher and a spring confined between said element andsaid body, indicating means with which said element registersto'indicate extent of adjustment of said element in terms of pressure,means for limiting theextent of axial movement of said expanding memberin one direction including an axially adjustable'member carried by saidbody, and means for indicating the extent of adjustment of saidadjustable member in terms of thickness of material to be removed from9, cylinder wall.

13. A cylinder grinding tool comprising a body, grinding members mountedin said body for expansion and contraction movements, an expandingmember carried by said body andmovable axially thereof to expand andcontract said grinding members, means for moving saidexpanding'meniberincluding an axially adjustable element on said;expanding member and a spring confined between said elementand saidbody, indicating means carriedby said body and with which said elementregisters to indicate extent of adjustment of said element in terms orpressure, mean's"'for limiting the extent of axial movementoisaidexpanding member in one di rection including an axially'adjustablemember carried by said body, and means including registering indicatingelements on said adjustable element and said adjustable member forindicating the extent or adjustment of said adjustable member in termsof thickness of material to be removed from a cylinder wall.

' 14. A cylinder grinding tool which comprises a body, grinding memberscarried by said body, means for expandingandcontracting said mem bers,and means fordriving said'body rotatably which includes a tubular memberextending axially through saidbody and rigidly secured to the lowerendthereof, adriving spindle of lesseroli; ameter than said tubular memberextending therethrough and threbeyond at one end, and means including ajoint giving universal action connecting theotherend o f'said spindletosaid body/ A cylinder grindingtool-which comprises a body, grindingmembers carried by said body,

m a for x andin 41d qnimetic d bers, and means for driving said bodyrotatably which includes a tubular member rigidly secured at one end tosaid body and projecting axially through said body and beyond one endthereof, means for rotatably driving said body which includes a spindleof less diameter than and mounted within said tubular member, meansaffording universal action connecting one end of said spindie to saidbody, said spin'd-le being of suflicient length to extend through andbeyond the projectinge'nd of said tubular member, and universal jointmeans on said spindle adapted for connection with a driving mechanism.

16. A cylinder grinding tool comprising a body, grinding members mountedin said body for expansion and contraction movements, a tubular membersecured to the bottom of said body and extending axially therethroughand therebeyond, an expander device supported by said tubular member foraxial slide movement and engaging said grinding members to expand andcontract the same as it is moved axially, means for moving said deviceaxially including an adjusting element on said device and a springbetween said device and said body, means carried by said tubular-memberfor limiting the axial movement of said device in expanding direction,means for driving the tool rotatably including a spindle of lesserdiameter than and extending through said tubular member, and meansincluding a universal joint connecting the lower end of said spindlewith the lower end of said tubular member.

17. A cylinder grinding tool comprising a body having spaced apart topand bottom plates, grind ing members supported by said plates formovement toward and from a cylinder wall to be ground, a tubular memberextending centrally through said plates andrigidly secured to at leastone of said plates and extending beyond one of said plates, an expandermember supported by said tubular member for axial movement to move saidgrinding membersltoward and from the cylinder wall, means for adjustingsaid expander member axially including an axially adjustable elementcarried by said expander member and a spring confined between saidelement and a part of said body, means for limiting the extent of axialadjustment of saidexpander member in one direction, and driving meansindependent of both said adjusting means including a spindle universallyconnected at one end to said tubular member and extending out throughthe project ing endthereof.

18. In a cylinder grinding tool, a body, abrasive members supported bysaid body for movement toward and from the; wall of the cylinder to beground, an axially shiftable exp andenunit carried by said body and;adapted to .suppo rtsaid a ra m mee sagai st ,m r men a m the cylinderwa l, ix- 15 e n aid asive mem ers and r ing e in from thecylinderwallandfinto supporting engagement, with said expander; unit, means; forshifting said expander unit, axially.- toward; he cylinder wallincluding an axially.- adiu table ,ele; ment carried by saidexpanderunit. and:-.a com pressible spring of greatenpower thansaidzspring meansand disposedbetween said body and said element, and means carriedbyvsaid body and adjustable axially thereof towariably limit, the extentof axial movement of said expanderrunlt in a direction to move saidabrasive members toward the cylinder wall.

19. A cylinder grinding tool comprising a body having a pair of endplates with radially directed grooves in their facing surfaces, anannular series of posts disposed between said grooves and rigidlyconnecting said end plates, abrasive carriers having end portionsslidably mounted in said grooves and having abrasive support means alongtheir outer edges, an axially shiftable expander unit mounted centrallyof said body and engaging the inner edges of said carriers to expand thelatter as said unit is shifted in one direction, means for axiallyshifting said unit, and means for yieldably opposing expansion movementof said carriers and for holding the same seated against said unit whichincludes a plurality of leaf springs, one for each of said posts,secured intermediate their ends to said posts with their opposite endsextending toward adjacent ones of said carriers, and spring supportelements on said carriers inwardly of said abrasive support means forsupporting the ends of said springs which are normally under tensiontending to yieldably move said carriers inwardly.

20. A cylinder grinding tool comprising a body, grinding members mountedin said body for expansion and contraction movements, a tubular membersecured to said body and extending axially therebeyond at one end, anexpander device supported by said tubular member for axial slidemovement and engaging said grinding members to expand and contract thesame as it is moved axially, means for moving said device axiallyincluding an adjusting element on said device and a spring between saiddevice and said body, means carried by the projecting end of saidtubular member for limiting the axial movement of said device inexpanding direction, means for driving thevtool rotatably including aspindle of lesser diameter than and extending through said tubularmember and means affording universal action connecting one end of saidspindle to said body.

21. A cylinder grinding tool comprising a body having spaced apart topand bottom plates, grinding members supported by said plates formovement toward and from a cylinder wall to be ground, a tubular memberextending centrally through said plates and rigidly secured to at leastone of said plates and extending beyond one of said plates, an expandermember supported by said tubular member for axial movement to move saidgrinding members toward and from the cylinder wall, means for adjustingsaid expanding member axially including an axially adjustable membercarried by said expander member and a spring confined between saidelement and a part of said body, means for limiting ,the extent of axialadjustment of said expander member in one direction, and driving meansindependent of both said adjustment means and including a spindleextending out through the projecting end of said tubular member anddrive-connected with the body by means affording universal action.

FREDERICK G. WACKER.

